QN9080 Enable Power Down unused memory

[kyleyang]

Hi pals

IAR IDE is my current compiler tool.

I try to add "POWER_EnablePD(kPDRUNCFG_PD_MEM9);" into my heart rate sample code to enable lower power consumption.

But when function execute to this "POWER_EnablePD" subroutine, system will crash.

I also try the demo example code "power_mode_switch" and it works.

What's the different between these two projects when implement "POWER_EnablePD" function?

[neoxiong · Accepted solution]

Hi, Kyle

In BLE connectivity project, the CSTACK is assigned to the end of SRAM region, while power_mode_switch demo assign CSTACK to somewhere middle of SRAM.

POWER_EnablePD(kPDRUNCFG_PD_MEM9) will power off the last memory block which is used for stack purpose in ble project. That's why you get system crash after calling that API. 

You can always change the link file in IAR for placement, then everything is fine after power down last block of SRAM.

In QN908XC_connectivity.icf, change below line

place in CSTACK_region           { block CSTACK };

to

place in DATA_region           { block CSTACK };

[kyleyang]

Hi Neo,

Really appreciate your help, its works.

I found a weird issue after compile project code.

I own two version of QN9080 SDK on hand, one is "QN908XB-0.6.1" and the other is the SDK beta.

The "readwrite" memory of SDK beta is much bigger than "QN908XB-0.6.1" and use the same type of project code.

Do you have any idea to resolve this issue to reduce ram size for lower power consumption?

I am Kyle, we can have a discuss in mail if possible.

Thanks.

kyleyang@wtmec.com